Growth of phosphorus-doped ZnTe thin films by molecular beam epitaxy using InP as the dopant source

P-doped ZnTe thin films were grown by MBE on ZnTe (100) substrates using InP as the P source under various InP fluxes. Secondary ion mass spectroscopy (SIMS) analyses showed that the P concentration in ZnTe thin films increased with increasing InP flux, although In atoms were also incorporated in the films. To suppress In incorporation, the outlet of the InP cell was modified by mounting a cap and a plate with small holes. As a result, In incorporation was significantly suppressed, resulting in an In concentration three orders of magnitude lower, as confirmed by SIMS, although the P concentration also decreased by almost one order of magnitude compared with the case without a cap. An acceptor-bound exciton (I-a) peak was observed at around 2.36 eV in the P-doped ZnTe thin film grown with a cap, and the I-a intensity increased after annealing, indicating the activation of P acceptors.

Automated summary

P-doped ZnTe thin films were grown using InP as the P source by MBE on ZnTe (100) substrates. SIMS analysis revealed that the P concentration in the films increased with increasing InP flux, accompanied by In incorporation. To suppress the In incorporation, the outlet of the InP cell was modified. The modified outlet successfully decreased the In concentration by three orders of magnitude, while the P concentration also decreased by one order of magnitude. An acceptor-bound exciton (I-a) peak at 2.36 eV was observed in the P-doped ZnTe thin film grown with a modified outlet, and the I-a intensity increased after annealing, indicating the activation of P acceptors.